[peechus]

Am considering new binding posts for my 3.7 maggies. Can quality after-market binding posts improve the sound over the cheesy steel thingy that Magnepan uses.

[Davey]

Those jacks get a bad rap in my opinion.  They have a full 3/4" cylinder bore (more than most) and the set screw allows to tighten wires creating a lot of connection force.  I think the fuseholder rivets and the spade lugs to the transducers are much more likely to create questionable connections in the Magnepan crossovers.

Cheers,

Dave.

[jk@home]

Cardas and Vampire seem to be popular brands used. If your 3.7s are like the other models, there isn't a whole lot of room behind the panel, so make sure you pick something out that is short, length wise.

I use Cardas Patented posts on my MMGs, like the simplicity. But there is more involved when installing. A small hole has to be drilled in between the two existing ones for the mounting bolt. I also use a stainless steel center allen bolt, bought from a local fastener supplier, instead of the regular steel one provided by Cardas.

[berni]

Hi,

I also think that the binding post are not worth of Maggies.
Doing a protective cover for the outboard XO of my 20.1 (protection for matchbox cars flying around ) I made some thoughts what else could be easily done and would have a positive effect.
- protective cover made out of alcantara or car cloth with foam to prevent vibration of the stainless XO box
- the stainless cover of the XO box will get  dampening inside with dynamate like material
- the tweeter attenuator which I don't use will be bridged - soldered fix

 I use the biwire connection, but if you look over how many of these lousy binding post the signal has to travel you get a shiver:
- first 4 of these to insert into the XO then 4 out into the round plug, which has a rather poor contact and on the other side again 4 post with the same contact , all of these secured with a screw, everything is high mass and can effect the signal
so we have 16 poor connections, +2 poor connections(attenuator) , 2 bridge jumpers plugs for the attenuator and 4 bad connection plugs to connect the XO with speakers.
My solution:
 - my speaker cable is chossen
 - I will take away the banana plugs on speaker side of  the cable, lead the cable throw the old binding post and solder it in the XO box, pull a plastic tube over the cable and secure the cable on the original binding post
- on the output from the XO box I will solder a rhodium banana plug which is made out of three parts and can be secured(fixed) with one of them on the XO box, so the banana is fixed permanently on the XO box
- the binding post on the speakers will be changed with low mass Eichmann Cablepods
- permanently solder the attenuator bridge

With this aproach   we got:
 16 poor connections, 4 bad connection plugs, 2 bridge (attenuator) and +2 poor connections  VS  4 connections with better banana plugs and better binding post, all other connections permanently soldered with still the capability to simply disattach the XO,
 the XO box dampened to prevent unwanted vibration and a protection against flying MFC (matchbox flying cars)

Everything mentioned is  per one side! I also tested the jumpers and old binding post with a small magnet!. The jumpers are full magnetic and also all of the screws in the original binding post. Not quite good in my opinion.
I think this can be called a small upgrade, what do you folks think about?

[josh358]

Am considering new binding posts for my 3.7 maggies. Can quality after-market binding posts improve the sound over the cheesy steel thingy that Magnepan uses.

Bad material but it shouldn't affect the sound if it's kept clean. Oxide layers or dirt, being semiconducting, will cause measurable, audible, and very unpleasant distortion.

[DaveC113]

Pomona makes a very good gold plated copper post for about $9.

http://www.pomonaelectronics.com/pdf/d3750-3760-3770_101.pdf

[berni]

Bad material but it shouldn't affect the sound if it's kept clean. Oxide layers or dirt, being semiconducting, will cause measurable, audible, and very unpleasant distortion.

A whole bunch of normal iron(magnetic) in jumpers, screws, and poor contacts  in the signal way shouldn't affect sound, especially on the tweeter side, ?
Why having this in the signal path if it is not needed and it may be audible? Cost again? Common.

[berni]

First material delivered and installed.
The Silencoat (similar to dynamat) will help the cover against vibrations.


the original wiring and binding posts



the new low mass tellurium bananas will be installed directly to the xo box



tested with a magnet, you can see what is used for the jumpers and binding post screws, without  them you have no contact( look at the left binding post)

[josh358]

A whole bunch of normal iron(magnetic) in jumpers, screws, and poor contacts  in the signal way shouldn't affect sound, especially on the tweeter side, ?
Why having this in the signal path if it is not needed and it may be audible? Cost again? Common.

The contacts will be fine if not oxidized and kept clean. What would they do? Their conductive behavior will be linear. And I don't think that saturation or hysteresis will be a problem in this application.

These aren't materials I would use in a design, but that's because I'd be concerned about oxidation -- they require more cleaning than other materials. Not because they'll sound any different if they're clean.

I sometimes think that if audiophiles could see how many contacts their beloved audio goes through in the studio, and how many hundreds of feet of very ordinary Belden or West Penn cable, they'd off themselves. But the pleasant truth is that, if maintenance is good and basic engineering protocols are observed, its inaudible.

[berni]

Say what you want. Steel is not even used as a conductor in the house power supply, all cables are copper or aluminium, why used it then in a HIGH END speaker directly in the signal way and in the top of the line one??
 Why always doing  everything against knowledge and defend wrong aproach?

[srb]

the new low mass tellurium bananas will be installed directly to the xo box

Those banana plugs actually look fairly high mass compared to something more minimalist like:
 
Multi-Contact LS4
 

 
or
 
Furez TSNT38NP
 

 
Steve

[berni]

Yes, they look, but they are hollow and very light! Because they will be the bridge between the XO and speaker, they must be a bit more ridgid . I would definetly go with this minimalist approach if there was not the problem  of screwing those banana plugs on the XO box. You will see what I mean in the next future, by this I will use 1/3 of bananas and 1/4 of binding posts.

[SteveFord]

I'm looking forward to seeing how this one progresses.
For those who don't know, Berni has rambunctious children to contend with as part of his design paramaters.

[josh358]

Say what you want. Steel is not even used as a conductor in the house power supply, all cables are copper or aluminium, why used it then in a HIGH END speaker directly in the signal way and in the top of the line one??
 Why always doing  everything against knowledge and defend wrong aproach?

It has something to do with having spent my entire professional life as an audio video engineer designing facilities that used connectors in the tends of thousands, I think. If I hadn't done everything against knowledge and defended the wrong approach, the rooms I decided would have worked. And we can't have that, can we.

I hope that the cables in your house electrical system aren't aluminum, or if they are, that they're properly installed, because houses with aluminum wiring have a nasty habit of burning down. And how many unplated copper contacts do you see in audio paths? None, right, that aren't plated? And yet they're used in your house electrical. These two materials have different characteristics that suit them for different applications, and if you don't know what those are, you can't make statements about a material's suitability. Steel, for example, is commonly used as a contact material where operating temperatures are high. Its conductivity is low. It must be carefully plated to prevent oxidation. But in those applications, it's the most suitable material for the job.

As it happens, I didn't say I would use Magnepan's approach. I think the little setscrew and Allen wrench are a pain. I did point out that if you keep the connectors in Maggies dirt- and oxide-free and tight, you won't be able to hear the difference between them and connectors made of the most precious and non-reactive of substances. They don't have any electrical characteristics that would make them audible in those applications: their conductivity is high enough, they aren't nonlinear, so where's the beef?

[SteveFord]

They're not fancy schmancy, that's what the deal is.
Better looking binding posts dress the old girls up plus screwing around with stuff like this is fun.

[josh358]

They're not fancy schmancy, that's what the deal is.
Better looking binding posts dress the old girls up plus screwing around with stuff like this is fun.

Oh, no objection to that, if I didn't have a million other things on my plate I'd do it myself. My only point was that this isn't going to make an audible difference, unless they're dirty or corroded or something. The interpanel connectors on my 1-D's got that way, they started to crackle when I moved them. Dirt and oxides are semiconducting and nonlinear distortion increases. Eventually, you get a frog-in-the-throat effect that's awful to hear.

[berni]

I hope that the cables in your house electrical system aren't aluminum, or if they are, that they're properly installed, because houses with aluminum wiring have a nasty habit of burning down. And how many unplated copper contacts do you see in audio paths? None, right, that aren't plated? And yet they're used in your house electrical. These two materials have different characteristics that suit them for different applications, and if you don't know what those are, you can't make statements about a material's suitability. Steel, for example, is commonly used as a contact material where operating temperatures are high. Its conductivity is low. It must be carefully plated to prevent oxidation. But in those applications, it's the most suitable material for the job.

As it happens, I didn't say I would use Magnepan's approach. I think the little setscrew and Allen wrench are a pain. I did point out that if you keep the connectors in Maggies dirt- and oxide-free and tight, you won't be able to hear the difference between them and connectors made of the most precious and non-reactive of substances. They don't have any electrical characteristics that would make them audible in those applications: their conductivity is high enough, they aren't nonlinear, so where's the beef?

Ok, I will go slowly.
- most of copper contacts are like you said plated and this is ok, but there are not a lot of them made out of stell
- at high temperatures we could use stell, but in the signal way to speakers? hot speakers?
- you have heard what oxidized contast have done, did they went from superb sounding to crackle in one sec. ?? Or did they deteriorate with time?
- what is or is  not audible is not the issue, if we don't want to prevent things that are common known in the first time, we can simple say nothing matters and nothing is audible, but more "not audible" things together can be a audible effect
- stell, plated or not is not a superb conductor for a speaker in the range of 10.000$ up

.

[DaveC113]

From Mundorf capacitor datasheet. Replacing steel with copper conductors WILL make an audible difference!

No steel
From now on, steel connectors are a thing of the past at MUNDORF because the use of steel as material for connectors
[word-wide standard for snap-ins] has many disadvantages: Among other things, steel connectors cause unwanted eddy
currents due to their magnetic properties, have a poor electric conductivity [σ25°C 6.2MS/m = 10.7% IACS = 160mΩ*mm2/
m] and a low thermal conductivity [λ25°C 50W/(m*K)]. In addition, the high elasticity [200 GPa] and hardness [7 Mohs] of
steel snap-in clamps are a permanent stress for the soldering joint which might reduce the quality of the joint.

[Hank]

What is "stell"?  If it's a new, high-end exotic metal/plating snake oil connector, I WANT 'em!  Cost is no object!

[josh358]

Ok, I will go slowly.
- most of copper contacts are like you said plated and this is ok, but there are not a lot of them made out of stell
- at high temperatures we could use stell, but in the signal way to speakers? hot speakers?
- you have heard what oxidized contast have done, did they went from superb sounding to crackle in one sec. ?? Or did they deteriorate with time?
- what is or is  not audible is not the issue, if we don't want to prevent things that are common known in the first time, we can simple say nothing matters and nothing is audible, but more "not audible" things together can be a audible effect
- stell, plated or not is not a superb conductor for a speaker in the range of 10.000$ up

.

Well, they wouldn't have oxidized (or gotten dirty) immediately, of course. The crackling was apparent when I moved the panels and at some point it was just there. This is a common issue with connectors and controls and can generally be solved with a cleaning. But it's obvious. There's a more gradual degradation of transparency that's more insidious. If you measure it, you will measure harmonic distortion. But the effect actually becomes worse than the measurements would suggest. The dirt or oxide is a semiconductor, and the junction forms a diode. The signal starts to conduct preferentially in one direction and the results are sonically very ugly indeed.

As to the sonics of steel, I don't think you'll find that eddy currents, hysteresis, or saturation make any difference in this application. There just isn't all that much self inductance. Conductivity isn't an issue either, it isn't like we're dealing with the output of a phono cartridge. The contact area is large and the connectors/jumpers as well, so the added resistance will be trivial. Neither do I think the rigidity of steel makes any difference in this application. The wires are clamped with a set screw under high pressure. Furthermore, being copper, they'll conform to the steel.

A connector has to be viewed as a system to determine whether a material is or isn't suitable.

About the only thing I can see that's problematic (besides the annoying set screw) is the plating. You don't want dissimilar metals in contact with one another because there's a potential difference and you can get electrolytic oxidation. The connectors should be gold plated. A crimped connection doesn't suffer from this problem, and the setscrew will pretty effectively "crimp" the soft copper to make an airtight seal. Still, since the cables are sometimes moved or removed, I'd feel more comfortable if there were gold plating on the speaker connectors, with the crimp where it belongs, in the lugs or banana plugs on the cable.